The present invention relates to a technology for calculating an environmental load of a product.
At the present time, environmental regulations such as, for example, restriction of hazardous substances (RoHS) and energy using products (EuP), are being strengthened, centered on Europe. These regulations entail a precise evaluation of environmental load of a product on the side of the manufacturer.
A method for evaluating the environmental load of a product is exemplified by a method for evaluating a chemical substance contained in the product and a life cycle assessment (LCA) for evaluating quantity of CO2 or the like discharged during a period of time from production to discarding of a product. This type of environmental impact evaluation is carried out from composition information indicating items from which the product is composed and environmental load information for each item. Specifically, for instance, in the case of evaluating a chemical substance, a manufacturer obtains chemical substance information on all of items described in the composition information of the product from the retailing enterprise (supplier) of the respective items. The manufacturer adds up the obtained chemical substance information and computes the chemical substances contained in the product, thereby calculating the environmental load.
In order to reliably comply with the laws and regulations, generally, the chemical substances are evaluated at two stages: at product design and after producing the product.
A technology for calculating the environmental load of the product at the design stage is disclosed in Japanese Patent Laid-open Publication number 2003-256504. Items are described in item codes in an item table used for calculating the environmental load of the product at the design stage. The respective item codes are in some cases associated with item numbers of a plurality of suppliers in order to optimize production lead time and cost. Namely, one item code represents, as the case may be, an item supplied by each of the plurality of suppliers, or a plurality of items supplied by one supplier. Therefore, the evaluation at the design stage involves envisaging a worst case among all the items that may be used, so that there will be no problem when any one of the items is used.
The evaluation of the environmental load after production is conducted with respect to items actually used in producing the product. Herein, as described above, there are cases in which one item code represents an item supplied by each of the plurality of suppliers and a plurality of items supplied by one supplier. Namely, even with an item specified by the same item code, there are cases in which the content of chemical substances contained in the item is different. The evaluation of the environmental load at the design stage is done on the assumption of the worst case. However, the evaluation of the environmental load after production involves accurately evaluating the chemical substances corresponding to the item composition for each product actually produced.
The environmental load of the product is tallied by multiplying the quantity of each used item by the environmental load of this item, and adding up for a product unit. Herein, the compositional information and the information on the items actually used for producing the product (actual results information), are created by a company itself. On the other hand, the environmental load information of the item is obtained from the supplier. Thus, the information on the items which compose the product and the environmental load information of each item have different registration sources. Hence, there might be a case where the usage quantity unit of the used quantity of an item does not match the registered unit of the environmental load information.
As a solution to this problem, a method can be considered in which the supplier is provided with an item table and the units used for the actual results information, and the environmental load information is registered in units designated by the supplier. There are cases in which the units described in the item table and in the actual results information, even of the same items, might differ depending on business division. In such cases, according to the method given above, the supplier must change and register the environmental load information for each delivery destination. As a result, there arises a problem in that the number of man-hours for registration by the supplier increases, which causes a delay in collecting the environmental load information.
An other solution is a method of changing the usage quantity unit of the item in accordance with the registration unit of the environmental load information registered by the supplier. The usage quantity of the item described in the item table is, however, utilized also for procuring the item and for production management, and the registration unit of the chemical substance information does not necessarily suit the purpose thereof. Hence, if the unit in the item table is changed, there arises a problem in that existing systems, such as a production management system, need reconfiguring, and the number of man-hours for developing the system increases.